Process of extracting tin from tin ores.



UNITED STATES HEINRICH BRANDENBURG, OF KEMPEN-ON-THE-RHINE, GERMANY.

PROCESS OF EXTRACTING TIN FROM? TIN OBES.

Specification. of Letters Patent.

ratelitasul a, 1907.

Application iiled October 26,1906. Serial No. 340,448.

To all whom it may concern:

Be it known that I, HEINRICH 'BRAN ENBURG, chemist, a subject of the King of Prussia, residing at 29 Moorenring, Kempen-on-the-Rhine, in the German Empire, have invented a new and useful Process for Extracting Tin from Tin Ores, Ashes, Waste Products, Residues, and other Tin-Containing Substances; and I do hereby declarethe following to be a full, clear, and exact description of the same. i

This invention relatesto an improved process for extracting tin from tin ore, ashes, waste products, residues, and other tin-containing substances of any composition.

As is well known tin is obtained from tin-stone by a dry process, viz. by smelting it with coal. The reduction takes place at a high temperature, and the temperature of smelting is so high that slag is formed. The formation of slag in processes hitherto known is even intentional, inorder to protect the tin reduced from tin ore, against oxidation by the air. It is well known that oxid of tin is distinguished by the property of being able to play the part of an acid as well as of a base, and consequently of easily passing into slag. It is chiefly the basic character of the oxid of tin which causes the formation of tin slag, the monoxid of tin.

becoming converted into silicate of tin with the silica of the charge or of the hearth. To that must be addedthe property of silicate of tin and of other slags, of dissolving dioxid and oxid of tin. The tin which has passedinto the slag can only be extracted from the latter at considerable expense and with great difficulty.

'The reducing process in such case takes place in such a manner that metallic raw or unrefined tin is obtained embedded in the loose, and not slagged, silica of the ore.

If the raw materialsj,'that is to say, the ore or any other tin containing substance, as: well as the reducing substance, are thoroughly mixed together in the form of powder and heated in a furnace to a temperature precluding any possibility of the formation of slag, the product is obtained in which the reduced raw' tin, containing as impurities chiefly iron, ap pears in the form of a powder. The monoxid of tin which was'foi-merly accessible in the chemical sense,

with difliculty has now been brought intoa powdered form, that is to say, into a state in.which the metal is in a very convenient form for any further chemical or electro-chemical treatment, and obviously it is necessary to take steps t'o,'prevent the reoxidation of the reduced metal in yiew of the fact, thatin in the formof powder, like most powdered metals, is easily liable to oxidation,

It is immaterial for the final result whether the reducing agent is solid, liquid or gaseous, and it goes without saying that the reduction could be preceded by a preparatory treatnlent, roasting, lixiviation and the like, according to the composition of the ore.

Having described my invention, what I claim as new,.,and des ire to secure by Letters Patent of the United States isz 1. A process forv extracting tin from tin ore or other tincontalning substances by reduction which consists in heating it'under reducing-conditions at a temperature sufli-.

the tin is obtained in the form or a powder and in a state suitable for mechanical, chemical or electrochemical treatment. l I

In witness whereof I have hereunto set my hand in the presence of two witnesses.

HEINRICH BRANDENBURG.

Witnesses: 5

AUGUST WAYIIANIJ," HEINRICH ZIMMERM ANN. 

